JP3920601B2 - Vacuum microwave thawing machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum microwave thawing machine that performs thawing by irradiating microwaves in a decompressed state to heat an object to be thawed.
[0002]
[Prior art]
A conventional vacuum microwave thawing machine is an apparatus for thawing an object to be thawed by irradiating microwaves in a pressure reduction process while repeatedly performing a pressure reduction process and a pressure reduction process. The machine includes a chamber for storing the material to be thawed, a vacuum pump for decompressing the chamber, a decompression means for decompressing the chamber decompressed by the vacuum pump, and irradiating the chamber with microwaves in the decompression step. A microwave generator.
[0003]
In such a vacuum microwave thawing machine, a rotating shaft is inserted into the bottom of the chamber, and a turntable on which the object to be thawed is placed is attached to the tip of the rotating shaft, and the object to be thawed is rotated together with the turntable. Then, the object to be thawed is evenly irradiated with microwaves and heated to perform thawing.
[0004]
[Problems to be solved by the invention]
By the way, in the conventional vacuum microwave thawing machine, the object to be thawed is heated by irradiating microwaves in the decompression process while repeating the decompression process and the decompression process, so the pressure in the chamber must be maintained. It is necessary to attach an air seal material to the insertion part of the rotating shaft of the turntable.
Further, since microwaves, which are a kind of electromagnetic waves, are irradiated from the microwave generator to the object to be thawed in the chamber, it is necessary to take measures to prevent the electromagnetic waves from leaking from the insertion portion of the rotating shaft of the turntable.
[0005]
However, in this type of vacuum microwave thawing machine, no specific proposal has been made regarding a technique related to an air seal structure and an electromagnetic wave shielding structure in the insertion portion of the rotary shaft of the turntable.
[0006]
Then, an object of this invention is to provide the vacuum microwave defroster which can perform reliably the air seal and electromagnetic wave shielding in the insertion part of the rotating shaft of a turntable.
[0007]
[Means for Solving the Problems]
The present invention has been proposed in view of the above, and according to the first aspect of the present invention, there is provided a chamber for storing an object to be thawed, a vacuum pump for reducing the pressure in the chamber, and a pressure regulating valve for returning the pressure in the chamber. In a vacuum microwave thawing machine having a microwave generator for irradiating microwaves into the chamber, irradiating microwaves in a reduced pressure state to heat the thawing object and defrosting,
A rotation shaft is inserted into the insertion portion established at the bottom of the chamber, a drive source is connected to the lower end of the rotation shaft, and a turntable for rotating the object to be thawed on the upper end of the rotation shaft is provided. An electromagnetic wave sealing member for blocking electromagnetic waves and an air sealing member for holding the pressure in the chamber are attached to the part, and the electromagnetic wave sealing member is disposed closer to the chamber than the air sealing member. Microwave defroster.
[0008]
According to a second aspect of the present invention, the electromagnetic wave sealing member has a space portion whose entrance is opened toward the outer peripheral surface of the rotating shaft, and newly enters the electromagnetic wave that enters the space portion and is reflected and returned. The vacuum microwave defroster according to claim 1, wherein a depth dimension of the space portion is set so that the electromagnetic wave is shifted by a half wavelength.
[0009]
According to a third aspect of the present invention, the space portion extends in a radial direction from an inlet / outlet facing the outer peripheral surface of the rotation shaft, and is bent in the axial direction of the rotation shaft from the middle thereof. Item 3. A vacuum microwave defroster according to Item 2.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing the appearance of the vacuum microwave defroster of the present embodiment. FIG. 2 is a schematic view showing the internal structure of the right side surface of the vacuum microwave defroster according to the present embodiment.
[0011]
As shown in FIG. 1, the housing 2 of the vacuum microwave thawing machine 1 according to the present embodiment is configured as a bowl-shaped device, and a food storage unit 3 for storing an object to be thawed such as frozen food is disposed on the top. In addition, a machine storage unit 4 for storing a drive motor, a vacuum mump, and the like, which will be described later, is disposed at the lower part, and a control unit 5 for storing a control device is provided at the uppermost part. The panel is provided with a display unit 6 for displaying the weight of the object to be thawed, the thawing time, and the like, and an operation unit 7 for inputting power on / off and various setting values. In addition, a caster 8 for facilitating the movement of the thawer 1 is provided on the lower surface of the casing 2 of the vacuum microwave thawer 1.
[0012]
As shown in FIGS. 1 and 2, the main body of the food container 3 in the vacuum microwave thawing machine 1 of the present embodiment is constituted by a hollow box-shaped chamber 10 having an opening on the front surface, and the chamber 10 is an electromagnetic wave. It is formed as a metal pressure-tight airtight container having an inner wall structure capable of blocking A door 11 capable of closing the inside of the chamber 10 in a sealed state is attached to the front opening of the chamber 10 so as to be openable and closable, for example, with the front right end as a hinge portion. On the left side of the front surface, a handle 12 that is gripped during the opening / closing operation is attached. Between the door 11 and the chamber 10, an electromagnetic wave sealing material for preventing electromagnetic waves from leaking to the outside and the airtightness in the chamber 10. It is equipped with an airtight sealing material that maintains the above.
[0013]
As shown in FIGS. 2 and 3, a rotating shaft 13 is vertically inserted in an insertion portion opened at the bottom of the chamber 10, and a cylindrical uneven Oldham coupling is formed at a lower end portion of the rotating shaft 13. 24 is connected to a motor with a speed reduction mechanism (driving source of the present invention) 16 through 24, and a table receiver 13a having an enlarged-diameter recess is formed at the upper end thereof, and a turntable is formed in the recess of the table receiver 13a. The turntable 15 is detachably attached to the rotary shaft 13 by inserting and seating a projecting attachment portion 15a formed at the center of the back surface of 15.
[0014]
As shown in FIG. 3, the rotary shaft 13 has a stepped portion having a lower step portion 32 b, a middle step portion 32 c, and an upper step portion 32 d that have a flange portion 32 a at the upper portion and are gradually expanded in diameter toward the inner periphery. It is inserted into the cylindrical housing 32, and is rotatably supported by an upper bearing 14a and a lower bearing 14b fixed at two locations in the upper and lower sides within the housing 32. A flange portion 32 a of the housing 32 is fixed by a fixing screw 28 to a housing mounting flange 10 a fixed to the lower portion of the chamber 10 via an O-ring 27.
[0015]
In the housing 32, ring-shaped oil seal members 17a and 17b are mounted on the upper and lower sides of the lower bearing 14b, and the upper oil seal member 17a is disposed on the lower step portion 32b and covers the periphery of the upper bearing 14a. The oil seal presser 18 provided in the state is pressed from above. A flange portion 18 a is formed on the upper portion of the oil seal retainer 18, and the flange portion 18 a is disposed on the middle step portion 16 c and is fixed to the housing 32 by a fixing screw 19. The oil seal member 17a is a gland packing having a lip having a taper formed on the outer peripheral surface. The oil seal member 17a is fitted to a ring having a taper inclined on the inner peripheral surface opposite to the taper. When acted, the lip squeezes and seals the rotary shaft 13. Even if the lip is brought into close contact with the outer peripheral surface of the rotating shaft 13 and exhibits a sealing function, the rotating shaft 13 can rotate without any problem.
[0016]
As these oil seal members 17a and 17b, a flexible material having lubricity such as fluorine rubber is preferable, and as an air seal member for holding the pressure in the chamber 10 at the insertion portion of the rotary shaft 13 of the turntable 15. It is functioning.
[0017]
The electromagnetic wave sealing member 25 disposed on the upper portion of the oil seal retainer 18 is a metal member having a concave longitudinal section, is inscribed in the upper step portion 32d of the housing 32, and surrounds the upper end portion of the upper bearing 14a. It is arranged in a covered state. This electromagnetic wave sealing member 25 has a space portion 29 formed with an entrance / exit facing the outer peripheral surface of the rotary shaft 13, and reflects microwaves that have entered the space portion 29 from the entrance / exit back into the space portion 29. Further, it has a function of canceling out the microwaves, and is fixed by a flange portion 26 a on the upper part of the substantially cylindrical electromagnetic wave shield presser 26. The flange portion 26 a is fixed to the housing 32 by a fixing screw 33. That is, the electromagnetic wave sealing member 25 cancels out the microwave that has newly entered by the microwave reflected in the space portion 29, thereby causing the electromagnetic wave to leak from the insertion portion of the rotary shaft 13 of the turntable 15. The electromagnetic seal member 25 is disposed closer to the chamber than the oil seal members 17a and 17b as air seal members in the insertion portion of the rotating shaft 13.
[0018]
Accordingly, the space 29 of the electromagnetic wave sealing member 25 has a depth dimension set so that the microwave returning from the entrance / exit and the newly entering microwave are shifted by a half wavelength. The space 29 in the present embodiment extends in the radial direction from the entrance / exit 29 ′ facing the outer peripheral surface of the rotating shaft 13, and is bent in the axial direction of the rotating shaft 13 from the middle thereof.
[0019]
In order to shift the length of the microwaves entering the space 29 by half a wavelength, that is, by shifting the phase of the wavelength by half, as shown in FIG. When the length of the extended space in the radial direction is L1, and the vertical length of the space bent from this space in the axial direction of the rotary shaft 13 is L2, the depth length (L1 + L2) from the entrance / exit 29 'is the wavelength. What is necessary is just to set so that it may become 1/4. That is,
L1 + L2 = λ / 4
It is represented by Here, λ: wavelength, C: speed of light, Hz: oscillation frequency,
λ = C / Hz = 3 × 10 ¹¹ /2.46×10 ⁹ = 121.95 mm
So,
λ / 4 = 121.95 / 4 = 30.5 mm
Is obtained. Therefore, it is necessary to set (L1 + L2) to 30 mm.
[0020]
Thus, when the dimension is set so that the electromagnetic wave returning toward the chamber 10 and the newly entering electromagnetic wave are shifted by a half wavelength, the electromagnetic waves cancel each other and are reliably blocked.
The material of the electromagnetic wave sealing member 25 is preferably a metal that easily reflects microwaves, such as an aluminum material.
[0021]
Further, in the insertion portion of the rotating shaft 13, the electromagnetic wave sealing member 25 is disposed on the chamber side of the oil sealing members 17a and 17b as air sealing members, so that the oil sealing members 17a and 17b having an air sealing function are arranged. This is because the electromagnetic wave permeability is taken into consideration, and the electromagnetic wave sealing and the air sealing can be reliably performed without giving the influence of the electromagnetic wave to the air sealing member.
[0022]
The chamber 10 is placed on the turntable 15 by irradiating the chamber with microwaves through a straight waveguide 20 and a reducer waveguide 21 that communicate with the chamber 10. A microwave generator 22 for heating the object to be thawed is flange-connected. In the present embodiment, a magnetron is employed as the microwave generator 22, and a pressure bulkhead capable of transmitting microwaves is interposed in the flange connection portion 23 between the straight waveguide 20 and the reducer waveguide 21. ing.
[0023]
A discharge detection sensor 30 is provided at the upper back of the chamber 10 to detect when a discharge occurs in the chamber due to the microwave irradiation. A UV sensor that is determined by detecting (UV) is employed. A vacuum pressure sensor 31 that detects the pressure in the chamber is provided in front of the upper portion of the chamber 10.
[0024]
An upper part of the chamber 10 includes an air release valve 40 that releases the pressure in the chamber to the atmosphere, and a pressure adjustment valve 41 that adjusts the pressure in the chamber. A decompression system 43 for decompressing the interior of the chamber is connected to the back surface of the chamber 10, and a vacuum pump 46 driven by a pump drive motor 45 is connected to the decompression system 43 via a check valve 44. . The air release valve 40 and the pressure regulating valve 41 are constituted by, for example, electromagnetic valves in order to enable opening / closing control by a control device housed in the control unit 5.
[0025]
FIG. 5 is a block diagram showing a control system in the vacuum microwave defroster of the present embodiment. The control device 50 housed in the control unit 5 is configured by, for example, a microcomputer that executes a control program recorded in the ROM 51, and the control device 50 includes a table drive motor 16 that rotationally drives the turntable 15. A power control system 52, a power control system 53 of a pump drive motor 45 that drives the vacuum pump 46, an open / close control system 54 of the atmospheric release valve 40, an open / close control system 55 of the pressure regulating valve 41, and the microwave A power supply control system 56 of the generator 22, a detection value input system 57 of the discharge detection sensor 30, a detection value input system 58 of the vacuum pressure sensor 31, an input system 59 such as a set value of the operation unit 7, A display output system 60 of the display unit 6 is connected, and the control device 50 controls the set values of the operation unit 7, the discharge detection sensor 30, and the vacuum pressure sensor. Based on the detected values or the like of the server 31 controls to drive the respective devices such as the pump drive motor 45 and the microwave generator 22 in accordance with a control program recorded in the ROM.
[0026]
Next, the vacuum microwave thawing method of the present embodiment performed using the vacuum microwave thawing machine 1 as described above will be described. FIG. 6 is an explanatory diagram showing a thawing cycle in the vacuum microwave thawing machine 1 of the present embodiment.
[0027]
As shown in FIG. 6, the vacuum microwave thawing machine 1 according to this embodiment irradiates microwaves M and M while repeatedly performing the decompression steps G, G ′, G ″... And the decompression steps F, F ′. It is a device for heating and thawing the object to be thawed, and the vacuum pump 46 continues to operate during the decompression process as well as the decompression process.
[0028]
As a preparation stage for thawing, first, the front door 11 is opened and an object to be thawed such as frozen food is placed on the turntable 15, and the door 11 is closed again to be in a sealed state. Contains the thaw. Note that the atmosphere release valve 40 and the pressure regulating valve 41 are closed.
[0029]
Next, the pump drive motor 45 is driven to operate the vacuum pump 46, and pressure reduction in the chamber 10 is started via the pressure reduction system 43. Then, since the lip of the oil seal 17 a is in close contact with the outer peripheral surface of the rotating shaft 13, the outside air is prevented from leaking into the chamber 10. Therefore, the pressure reduction degree gradually decreases from 101.3 kPa (760 Torr) of atmospheric pressure through the point A, and the pressure reduction step G is performed to the pressure reduction equilibrium region B. In this pressure reduction step G, the material to be thawed is pre-dried. .
[0030]
Here, the decompression equilibrium region is a region in which the degree of decompression with respect to a certain time is extremely reduced. For example, the degree of decompression (ΔP) in 30 seconds (Δt) is ΔP / Δt <13.3 Pa (0.1 Torr). Although it is sometimes grasped that the decompression equilibrium region has been reached, the equilibrium pressure in the decompression equilibrium region rises and falls due to the saturated vapor pressure in the chamber. Note that whether or not the decompression equilibrium region has been reached is determined by the control device based on the pressure signal from the vacuum pressure sensor 31.
[0031]
After performing the decompression step G to the decompression equilibrium region B, the pressure regulating valve 41 is opened at a predetermined opening degree to be described later, and the process proceeds to the decompression step F. The degree of decompression in the decompression step F causes vacuum discharge. The microwave irradiation M by the magnetron 22 is started and set in advance at the point C after exceeding the lower limit P1 [set to 1.33 kPa (10 Torr) with some margin in this embodiment] When the pressure is restored to the return pressure upper limit value D, the control device closes the pressure regulating valve 41 based on the pressure signal from the vacuum pressure sensor, and then proceeds to the pressure reducing step G ′ again. Then, the object to be thawed is heated by continuing the microwave irradiation M by the magnetron 22 up to the point A ′ before reaching the lower limit P1 at which the degree of decompression does not cause vacuum discharge. Stop irradiation.
[0032]
Even if the microwave is irradiated, as described above, even if the microwave leaks to the outside through the insertion portion at the bottom of the chamber 10, particularly through the gap around the rotation shaft 13, it is canceled by the space portion 29. It will be. Therefore, the microwave does not leak from the chamber 10 to the outside.
[0033]
In the present embodiment, the lower limit P1 of the degree of decompression that does not cause vacuum discharge is set to 1.33 kPa (10 Torr) as described above. That is, at the point C after the degree of decompression in the decompression step F exceeds 1.33 kPa (10 Torr), the microwave irradiation M by the magnetron 22 is started and the decompression is restored to the preset decompression upper limit D. Then, the process proceeds to the decompression step G ′ again, and the microwave irradiation M by the magnetron is continued to the point A ′ just before the degree of decompression reaches 1.33 kPa (10 Torr) to heat the material to be thawed. As described above, since the microwave irradiation M is performed from the middle of the decompression process F to the decompression process G ′, one thawing cycle including the decompression process and the decompression process is performed as compared with the conventional case where irradiation is performed only in the decompression process. A sufficient irradiation time can be secured.
[0034]
The return pressure upper limit value D is a variable pressure value set by the output of the magnetron 22 that irradiates microwaves, the pressure reduction capability of the vacuum pump 46, and the volume of the chamber 10, and in this embodiment, the throttle of the pressure regulating valve 41 By adjusting the throttle of the valve 41 ′, it is set to 6.66 kPa (50 Torr). Therefore, when the pressure is restored to 6.66 kPa (50 Torr), the leak from the pressure regulating valve 41 balances with the suction capacity of the vacuum pump 46, and the pressure rises by maintaining 6.66 kPa (50 Torr) unless the pressure regulating valve 41 is closed. I do not.
[0035]
In the present embodiment, the pressure value of the decompression upper limit D is appropriately set in accordance with the output of the magnetron 22 that irradiates the microwave, the decompression capability of the vacuum pump 46, and the volume of the chamber 10, so that the vacuum discharge The microwave irradiation time without excess or deficiency can be taken before entering the generation area, and the pressure can be reduced efficiently.
[0036]
In this embodiment, as a means for detecting that the return pressure upper limit value D has been reached, it is detected by a signal from the vacuum pressure sensor 31 so that the control device closes the pressure regulating valve 43 and proceeds to the pressure reducing process. Although configured, the present invention is not limited to this, and may be stopped by timer control.
[0037]
After the microwave irradiation is stopped, the object to be thawed is sublimated and cooled in the decompression process from the point A ′ to the decompression equilibrium region B ′. In this way, after the object to be thawed is heated by irradiating the microwave to the point A ′ in the decompression step G ′, the object to be thawed is sublimated and cooled in the decompression process from the point A ′ to the decompression equilibrium region B ′. When the object to be thawed is heated by irradiating microwaves, the temperature of the surface part of the object to be thawed becomes higher than the temperature of the center part, and if heating is continued as it is, there will be inconveniences such as drip on the surface part. This is because the surface portion is cooled by sublimation to reduce the temperature difference between the inside and outside.
[0038]
That is, when sublimation starts, the latent heat of vaporization is taken away and the temperature of the surface portion decreases, and the heat of the surface portion moves to the central portion (heat conduction) to raise the temperature of the central portion. As a result, the temperature of the material to be thawed is made uniform, and the temperature of the material to be thawed rises as a whole, and thawing is promoted. In addition, since the temperature of the material to be thawed is made uniform, thawing of the material to be thawed is promoted as a whole, so that thawing partially proceeds and drip is generated or microwaves concentrate on this drip. Can be prevented.
[0039]
In the present embodiment, the process proceeds to the decompression step F, and the microwave is generated at the point C after the decompression degree of the decompression step F exceeds 1.33 kPa (10 Torr), which is the lower limit P1 at which no vacuum discharge occurs. Irradiation M is started, and after returning to 6.66 kPa (50 Torr), which is a preset decompression upper limit D, the process proceeds to the decompression step G ′ again, and the degree of decompression is the lower limit P1 that does not cause vacuum discharge. A thawing cycle in which microwave irradiation M is continuously heated up to a point of 1.33 kPa (10 Torr) before a certain A ′, and after the microwave irradiation M is stopped, sublimation cooling is performed in a decompression process to a decompression equilibrium region B ′. Is repeated as one cycle.
[0040]
That is, in FIG. 6, after the decompression step G ′ is performed up to the decompression equilibrium region B ′, the process proceeds to the decompression step F ′, and the decompression degree of the decompression step F ′ is the lower limit value P1 at which no vacuum discharge occurs. At the point C ′ after exceeding 33 kPa (10 Torr), the microwave irradiation M ′ is started again, and after returning to 6.66 kPa (50 Torr) which is a preset decompression upper limit D ′, the pressure is reduced again. The process proceeds to step G ″, and the microwave irradiation M ′ is continuously heated until the pressure reaches 1.33 kPa (10 Torr) of A ″ which is the lower limit P1 at which the degree of decompression does not cause vacuum discharge. After the irradiation is stopped again, a defrosting cycle for sublimation cooling in the decompression process up to the decompression equilibrium region B ″ is performed as the second cycle. The decompression characteristics in each decompression process F, F ′. 41 'installation Because it depends on, constant in each thawing cycle, i.e., the curve of the condensate pressure curve is constant in each thawing cycle, which makes it possible to perform stable thawed.
[0041]
As shown in FIG. 6, when such a thawing cycle is repeated, the saturated vapor pressure in the chamber 10 increases as the temperature of the material to be thawed rises, so that the decompression equilibrium regions B, B ′, B ″. The depressurization degree of the above shows a phenomenon of increasing sequentially as the thawing cycle is repeated. Therefore, when the depressurization degree in the depressurization equilibrium regions B, B ′, B ″. That is, the desired thawing temperature can be set by setting the saturated vapor pressure region, and if the depressurization equilibrium is reached in this set region, the thawing operation is terminated assuming that the desired thawing temperature has been reached. The number of repetitions of the thawing cycle until reaching the set region also depends on the mass of the material to be thawed, the output of the magnetron 22, the decompression capacity of the vacuum pump 46, and the like. In this embodiment, P2A in FIG. When the pressure value is 480 Pa (3.6 Torr), the pressure value of P2B is 453 Pa (3.4 Torr), and the degree of pressure reduction in the pressure reduction equilibrium region B, B ′, B ″... Reaches a value between P2A and P2B Then, assuming that the temperature of the object to be thawed has reached about −3 ° C., the thawing cycle is completed.
[0042]
When the controller 50 determines the end of the thawing cycle, the air release valve 40 is opened, the power source of the pump drive motor 45 is shut off, the vacuum pump 46 is stopped, and the inside of the storage chamber 9 returns to atmospheric pressure. The door 11 can be opened, and the material to be thawed that has been thawed to about −3 ° C. can be taken out of the chamber 10.
[0043]
When a discharge phenomenon occurs in the chamber 10 for some reason, the discharge detection sensor 30 detects this by the generation of UV, and the control device 50 forces the magnetron 22 through the power supply control system 56. Thus, the inner wall of the chamber 10 is prevented from being damaged.
[0044]
Moreover, although the to-be-thawed material was demonstrated as frozen food in the said embodiment, the to-be-thawed material thawed by this invention is not limited to food, Blood, serum, semen, a medicine, etc. may be sufficient.
[0045]
【The invention's effect】
As is clear from the above description, the vacuum microwave defroster of the present invention has the following excellent effects.
That is, according to the first aspect of the present invention, the electromagnetic wave sealing member for blocking electromagnetic waves and the pressure in the chamber are inserted into the insertion portion of the rotating shaft of the turntable that rotates by placing an object to be thawed in the chamber. By attaching an air seal member for holding the air seal, the air seal and electromagnetic wave shielding at the insertion portion can be reliably performed.
And since an electromagnetic wave sealing member is arrange | positioned at the chamber side rather than an air seal member, an electromagnetic wave seal and an air seal can be performed reliably, without giving the influence of an electromagnetic wave to an air seal member. Therefore, even if the material of the air seal member is a material that is easily affected by microwaves, it can be used.
[0046]
According to the invention described in claim 2, since the depth dimension of the space portion of the electromagnetic wave seal member is set so that the returning microwave and the newly entering microwave are shifted by half wavelength, It is possible to reliably block the microwave that is about to leak from the insertion portion without any trouble.
[0047]
According to the invention of claim 3, the space portion of the electromagnetic wave sealing member extends in the radial direction from the entrance facing the outer peripheral surface of the rotating shaft, and is bent in the axial direction of the rotating shaft from the middle thereof. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a front view showing an appearance of a vacuum microwave defroster according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing the internal structure of the right side surface of the vacuum microwave defroster of the present embodiment.
FIG. 3 is a schematic view showing a structure of an insertion portion of a rotary shaft of a turntable in the vacuum microwave defroster of the present embodiment.
FIG. 4 is a schematic view for explaining dimension setting of an electromagnetic wave sealing member in the vacuum microwave defroster of the present embodiment.
FIG. 5 is a block diagram showing a control system in the vacuum microwave defroster of the present embodiment.
FIG. 6 is an explanatory diagram showing a thawing cycle in the vacuum microwave thawing machine of the present embodiment.
[Explanation of symbols]
1 Vacuum microwave thawing machine
2 Case
3 food storage department
4 Machine storage
5 Control unit
6 Display section
7 Operation part
8 casters
10 chambers
10a Housing mounting flange
11 Door
12 Handle
13 Rotating shaft
13a Table holder
14a Top bearing
14b Lower bearing
15 Turntable
15a Mounting part
16 Table drive motor
17a, 17b Oil seal member
18 Oil seal presser
18a flange
19 Fixing screw
20 Straight waveguide
21 Reducer Waveguide
22 Microwave generator (magnetron)
23 Flange connection
24 Oldham coupling
25 Electromagnetic wave sealing member
26 Electromagnetic shield presser
26a Flange part of electromagnetic wave shield presser
27 O-ring
28 Fixing screw
29 Space
29 'doorway
30 Discharge detection sensor
31 Vacuum pressure sensor
32 Housing
32a Housing flange
32b Lower part
32c Middle section
32d Upper stage
33 Fixing screw
40 Atmospheric release valve
41 Pressure regulating valve
43 Depressurization system
44 Check valve
45 Pump drive motor
46 Vacuum pump
50 Control device
51 ROM
52 Power control system for table drive motor
53 Power supply control system for pump drive motor
54 Opening / closing control system of air release valve
55 Pressure control valve open / close control system
56 Power source control system for microwave generator
57 Detection value input system of discharge detection sensor
58 Detection value input system of vacuum pressure sensor
59 Input system for operating unit settings, etc.
60 Display output system of display unit

Claims (3)

A chamber containing a material to be thawed, a vacuum pump for reducing the pressure in the chamber, a pressure regulating valve for returning the pressure in the chamber, and a microwave generator for irradiating microwaves into the chamber. In a vacuum microwave thawing machine that performs thawing by irradiating microwaves and heating the material to be thawed,
A rotation shaft is inserted into the insertion portion established at the bottom of the chamber, a drive source is connected to the lower end of the rotation shaft, and a turntable for rotating the object to be thawed on the upper end of the rotation shaft is provided. An electromagnetic wave sealing member for blocking electromagnetic waves and an air sealing member for holding the pressure in the chamber are attached to the part, and the electromagnetic wave sealing member is disposed closer to the chamber than the air sealing member. Microwave thawing machine. The electromagnetic wave sealing member has a space portion whose entrance is opened toward the outer peripheral surface of the rotation shaft, and the electromagnetic wave that enters the space portion and is reflected and reflected is shifted by a half wavelength from the newly entering electromagnetic wave. The vacuum microwave defroster according to claim 1, wherein a depth dimension of the space portion is set. The vacuum microwave thawing according to claim 2, wherein the space portion extends in a radial direction from an inlet / outlet facing the outer peripheral surface of the rotating shaft and is bent in the axial direction of the rotating shaft from the middle thereof. Machine.

Images